Stacked caps with connecting stems

ABSTRACT

A plurality of stacked fastener caps, each having a cap body. The cap body has first and second faces joined by a perimeter of the cap body, and adjacent faces of adjacent caps are joined by at least one connecting stem. The adjacent caps and connecting stems are integrally molded as a unit as by injection molding. One or both of the first and second faces may be planar. One of the first or second faces may be concave and the other may be convex. One or both of the first and second faces may have first and second thicker portions with a transverse groove interposed therebetween.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 13/490,359(filed Jun. 6, 2012), entitled “Stacked Caps with Connecting Stems”,fully included by reference herein, and claims priority benefit thereof.Parent application Ser. No. 13/490,359 is due to issue on Mar. 13, 2018,as U.S. Pat. No. 9,915,282.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO COMPACT DISC(S)

Not applicable.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates, in general, to fasteners and fastenercaps used as washers for holding roofing paper, insulation wrap, andcoverings to houses, lumber, and other articles in the constructionindustry, and, in particular, to stacks of such fastener caps that areloaded into magazines used in manual staplers and fastener applicatorsin the construction industry.

2. Description of Related Art

A conventional cap feeding device generally includes a cap container anda base having a channel. The base extends between the cap container anda position under the nose of the nail gun. Caps are fed into the channelof the base from the cap container and pushed to the position under thenose of the nail gun. When the gun is triggered, a nail penetrates anddislodges the cap under the nose of the nail gun and protrudes into theunderlying roof structure. The feeding of the caps under the nose of thenail gun is coordinated with the ejection of the nails through the noseof the nail gun, so that a cap is placed under the nose of the gunbefore the gun is triggered to expel a nail. Well-known cap feeding andnailing devices, and stacked assemblies of roofing caps for use therein,are disclosed in Lamb, U.S. Pat. No. 7,090,455 (issued Aug. 15, 2006;hereinafter, the “Lamb patent”), fully incorporated by reference herein.The coaxially-stacked caps disclosed in this Lamb patent have theadvantage that a stack of caps can be quickly loaded into the nailer'smagazine as a stacked unit, rather than being inserted one-by-one intothe magazine.

Many approaches are known in the prior art for quickly loading a stackof fastener caps into the nailer's magazine. Some approaches use anaxially-disposed longitudinal rod or string to hold the stack of capstogether while inserting the stack of caps into the nailer's magazine,and then the rod or string is removed, leaving the stack of caps in themagazine. Because there is nothing holding adjacent caps together afterthe rod or string is removed, these approaches have the disadvantagethat, once inserted into the magazine, the caps cannot be removedwithout becoming unstacked, making reinsertion into the magazine verydifficult as the caps have to be re-inserted one by one.

One embodiment of stacked caps disclosed in the Lamb patent, namely, thefifth embodiment shown in FIGS. 20-24 of the Lamb patent, has been shownto be a great improvement over the prior art. In this embodiment, astacked assembly of caps is placed into a sled and then portions of theouter circumference of adjacent caps in the stack are melted together asby heating with hot air or by using a laser. As a bottommost cap isejected from the magazine by a well-known pusher, the bottommost cap issheared from the stack of caps and is then moved into position in thenailer and subsequently nailed. Because portions of the outercircumference of adjacent caps remain melted together until shearedapart during nailing, the stack of caps can readily be removed as a unitfrom the nailer's magazine and will still remain together as a stackedassembly of caps, thereby permitting easy reinsertion of the stack ofcaps into the magazine.

While this assembled stack of caps, with portions of the outercircumference of adjacent caps being melted together, has been shown tobe a great improvement over the prior art, it is rather labor intensiveto manufacture. The caps are individually molded using well-knowninjection molding techniques, and, when the halves of the injection moldseparate and the caps are ejected from the mold using well-known ejectorpins in the mold, the caps are ejected onto a screen or plate below themold. The ejected caps then have to be manually gathered and inserted asa stack into a sled so that portions of the outer circumference ofadjacent caps can be melted together as by heating with hot air or byusing a laser, using the technique disclosed in the Lamb patent.

It is therefore desirable to have an improved assembly of stacked capsthat do not have to be manually gathered and inserted as a stack into asled for becoming joined together.

A prior art approach is known for joining a sequence of fastener caps ina linear string, as disclosed in Omli, U.S. Pat. No. 5,947,362 (issuedSep. 7, 1999; hereinafter the “Omli patent”), fully included herein byreference. FIG. 13 of the Omli patent shows a linear string of fastenercaps that are molded as a continuous strip in which a connecting piececonnects the perimeter of one cap to the perimeter of an adjacent cap.While such continuous linear strips of fastener caps have the advantagethat the strip can be molded as a unit without excessive manualassembly, such continuous linear strips of fastener caps have the greatdisadvantage that they must be fed from a bulky spool, rather than froma compact magazine as preferred by the construction industry, therebyrequiring a complex and bulky feed mechanism as disclosed in the Omlipatent.

It is therefore desirable to have an improved assembly of stacked capsthat can be injection molded as a unit, and which are stacked ratherthan being in a continuous linear strip.

BRIEF SUMMARY OF THE INVENTION

The present invention is a coaxially-stacked assembly of fastener capshaving shearable connecting stems between adjacent caps, in which thestacked assembly of fastener caps can be molded as an integral stackedunit.

It is an object of the present invention to provide a coaxially-stackedassembly of fastener caps in which the stacked assembly of fastener capscan be molded as an integral stacked unit.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a side view of stacked caps of a first embodiment of thepresent invention, which is substantially cylindrically symmetric.

FIG. 2 is a view of a bottom or second face of a cap of the firstembodiment of the present invention, taken along the line 2-2 shown inFIG. 1. The view of the top or first face is the same as shown in FIG. 2except for the omission of the “draft” or “ridge” portion on the topface.

FIG. 3 is a simplified sectional view of the halves of the injectionmold used to make the first embodiment of the present invention, shownseparated with the caps removed, and with injection passageways andejector pins being omitted in the drawing figure for purposes ofsimplicity.

FIG. 4 is a right-facing transverse sectional view of the injection moldused to make the first embodiment of the present invention, taken alongthe line 4-4 shown in FIG. 3. The left-facing transverse sectional viewof the injection mold is similar to the view shown in FIG. 4 except forthe omission of the mold cavity for the “draft” or “ridge” portion shownin FIG. 4.

FIG. 5 is a view of a cap of a second embodiment of the presentinvention.

FIG. 6 is a right-facing transverse sectional view of the halves of theinjection mold used to make the second embodiment of the presentinvention, similar to the view of FIG. 4.

FIG. 7 is a side view of stacked caps of a third embodiment of thepresent invention, which is substantially cylindrically symmetric.

FIG. 8 is a view of a bottom or second face of a cap of the thirdembodiment of the present invention, taken along the line 8-8 shown inFIG. 7.

FIG. 9 is a view of a top or first face of a cap of the third embodimentof the present invention, taken along the line 9-9 shown in FIG. 7.

FIG. 10 is a simplified sectional view of the injection mold used tomake the third embodiment of the present invention, shown separated withthe caps removed, and with injection passageways and ejector pins beingomitted in the drawing figure for purposes of simplicity.

FIG. 11 is a right-facing transverse sectional view of the halves of theinjection mold used to make the third embodiment of the presentinvention, taken along the line 11-11 shown in FIG. 10.

FIG. 12 is a left-facing transverse sectional view of the halves of theinjection mold used to make the third embodiment of the presentinvention, taken along the line 12-12 shown in FIG. 10.

FIG. 13 is a side view of stacked caps of a fourth embodiment of thepresent invention.

FIG. 14 is a view of a bottom or second face of a cap of the fourthembodiment of the present invention, taken along the line 14-14 shown inFIG. 13.

FIG. 15 is a view of a top or first face of a cap of the fourthembodiment of the present invention, taken along the line 15-15 shown inFIG. 13.

FIG. 16 is an upward-looking view of one of the halves of the injectionmold used to make the fourth embodiment of the present invention, andwith injection passageways and ejector pins being omitted in the drawingfigure for purposes of simplicity. The downward-looking view of theother of the halves of the injection mold used to make the fourthembodiment is substantially similar to the view shown in FIG. 16.

FIG. 17 is a right-facing transverse sectional view of the halves of theinjection mold used to make the fourth embodiment of the presentinvention, similar to the view of FIG. 11.

FIG. 18 is a is a left-facing transverse sectional view of the halves ofthe injection mold used to make the third embodiment of the presentinvention, similar to the view of FIG. 12.

FIG. 19 is a side sectional view of the cap of the fourth embodiment ofthe invention being used to hold a covering such as roofing paper to aboard with a staple therethrough.

FIG. 20 is a side view of stacked caps of a fifth embodiment of thepresent invention.

FIG. 21 is a view of a bottom or second face of a cap of the fifthembodiment of the present invention.

FIG. 22 is a view of a top or first face of a cap of the fifthembodiment of the present invention.

FIG. 23 is an upward-looking view of one of the halves of the injectionmold used to make the fifth embodiment of the present invention, andwith injection passageways and ejector pins being omitted in the drawingfigure for purposes of simplicity. The downward-looking view of theother of the halves of the injection mold used to make the fifthembodiment is substantially similar to the view shown in FIG. 23.

FIG. 24 is a right-facing transverse sectional view of the halves of theinjection mold used to make the fifth embodiment of the presentinvention, similar to the view of FIG. 17.

FIG. 25 is a left-facing transverse sectional view of the halves of theinjection mold used to make the fifth embodiment of the presentinvention, similar to the view of FIG. 18.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-4, the first embodiment 20 of the present inventionis seen to be a plurality of stacked fastener caps 22, with each caphaving a cap body 24. Each cap 22 is substantially identical to eachother cap 22, so that a description of one suffices for all, except thatthe end caps only have a single connecting stem (hereinafter described)because the end caps only have an adjacent cap on one side and not theother. Cap body 24 is preferably about 0.070 inches (1.8 mm) thick andhas a top or first face 26 on one side and a bottom or second face 28 ona second side spaced from the first face 26, and preferably one or bothof first or second faces 26, 28 are substantially planar, although oneor both of first or second faces may have a slight peripheralperpendicular “draft” or ridge portion 27 (described hereinbelow)extending from the face, it being understood that this ridge portion 27is not considered to make the first or second face substantiallynon-planar. The cap body 24 has a perimeter 30 joining the first face 26to the second face 28. While each cap 22 is shown as a circular disc,preferably about 0.978 inches (2.48 mm) in diameter so as to fit instandard-sized cap magazines, it shall be understood that other shapes,such as rounded rectangles, may be used for the caps 22 of the presentinvention. Such rounded rectangle shapes are shown, for example, inLamb, U.S. Design Pat. No. D593,391 (issued Jun. 2, 2009), fullyincluded herein by reference.

Adjacent faces 26, 28 of adjacent caps 22 are joined by at least oneconnecting stem 32, preferably axially disposed in the center of thecaps as shown, and preferably about 0.025 inches (0.64 mm) in diameter.Each stem 32 needs to be sufficiently flexible so as to allow thestacked caps to compress together when placed in the magazine of anailer, and also needs to be shearable so that, when the bottommost capof the stack is pushed into nailing position from the magazine, the stem32 will shear or break to free the bottommost cap from the stack. Thelength of each stem 32, and thus the gap between adjacent caps 22 whenthe stack is not compressed, is preferably about 0.060 inches (1.5 mm).As later explained hereinbelow, the common feature of all embodiments ofthe present invention is that all embodiments have at least oneconnecting stem (e.g., stem 32) joining adjacent faces of adjacent caps.

FIG. 3 is a simplified sectional view of the first and second halves 34,36 of the injection mold 38 used to make the first embodiment 20 of thepresent invention, and is shown separated with the caps removed. Itshall be understood that well-known injection passageways and ejectorpins are omitted from the drawing figures of the injection mold forpurposes of simplicity. In a manner well-known to those skilled in theart, each of the halves of the injector mold preferably has well-knowninjector pins (not shown) for ejecting the molded caps from the mold,and the operation of the injector pins of one half of the injection moldis sequenced with the operation of the injector pins of the other halfof the injection mold so that the caps are first ejected from one halfof the mold and then from the other so that the connecting stems of thecaps do not shear as might happen if some caps were ejected from onehalf of the mold while other of the caps remained in the other half ofthe mold. Additionally, to reduce the shearing of the caps duringejection, preferably each cap of all embodiments has a slight “draft” orridge portion 27 on one side of the cap so that the cap is betterretained into one half of the injection mold during ejection than in theother half of the injection mold. Each half of the injection moldrespectively has a plurality of semi-circular cavities 40, 42 thattogether, when the injection mold is closed, form a circular cavity formolding the bodies 24 of caps 22. Each half of the injection moldrespectively further has a semi-circular channel 44, 46 that together,when the injection mold is closed, form a circular passageway betweenadjacent cavities 40, 42 to create the connecting stems 32. Preferably,one of the halves of the injection mold has a recessed cavity 48 forforming the ridge portion 27 of each cap in the mold.

In contrast to prior art stacked cap assemblies, the assembly 20 ofstacked caps 22, as with all embodiments, is integrally molded byinjection molding, with all caps in the assembly and the connectingstems being integrally molded as a unit. Preferably there may be 55 capsin each stack to match the magazine size of existing nailers, but itshall be understood that the injection mold can accommodate making moreor fewer caps in each stack simply by changing the number of cavities40, 42 provided in the mold. Preferably the plastic used to mold allembodiments of the stacked caps 22 is well-known High-DensityPolyethylene (“HDPE”) plastic, and a filler may be added to the plasticto ensure that the connecting stems 32 shear properly without excessivestretching. Because the stacked assembly 20 is integrally molded as aunit, no manual assembly of individual caps into a sled is requiredduring manufacture, and the stacked assembly 20 is ready to be packagedfor sale when it is ejected from the injection mold.

As a variant on the present invention, a second embodiment cap 22′ isshown in FIG. 5. The only difference between second embodiment cap 22′and first embodiment cap 22 is that second embodiment cap 22′ has aplurality of connecting stems 32′ between adjacent caps 22′, shown inFIG. 5 as three connecting stems 32′ between adjacent caps 22′. It shallbe understood that the plurality of connecting stems 32′ can be of othernumbers, such as two or more than three, other than just three as shownin FIG. 5. It shall be understood that the third, fourth, and fifthembodiments, hereinafter described, can also, in like manner as thesecond embodiment, have a plurality of connecting stems between adjacentcaps.

FIG. 6 shows the first and second mold halves 34′, 36′, of the injectionmold 38′ used to make the second embodiment cap 22′. The only differencebetween first and second mold halves 34′, 36′ and first and second moldhalves 34, 36 is that first and second mold halves 34′, 36′ respectivelyhave a plurality of semi-circular channels 44′, 46′ for forming theplurality of connecting stems 32′.

Referring to FIGS. 7-25 of the drawings, third, fourth, and fifthpreferred embodiments of the present invention are shown. There are manysimilarities between the various embodiments, and only the differencesbetween the embodiments will be discussed in detail, it being understoodthat similar structure for the various embodiments serves similarpurpose. The reference numerals for the various parts of the third,fourth, and fifth embodiments shall be understood to have a prefixidentifying the particular embodiment (e.g., “3.”, “4.”, “5.”) and asuffix identifying the particular structure (e.g., “20”, etc.) similarto the un-prefixed reference numerals of the first embodiment, such thatreference numerals with the same suffix are understood to be similarstructure particular to each of the different embodiments (e.g., “3.20”,“4.20”, “5.20”).

Referring to FIGS. 7-12, the third embodiment 3.20 of the presentinvention is seen to be a plurality of stacked fastener caps 3.22, witheach cap having a cap body 3.24. Each cap 3.22 is substantiallyidentical to each other cap 3.22, so that a description of one sufficesfor all, except that the end caps only have a single connecting stem(hereinafter described) because the end caps only have an adjacent capon one side and not the other. The substantial difference between thefirst embodiment 20 and the third embodiment 3.20 is that the thirdembodiment has a convex top or first face 3.26 and a concave bottom orsecond face 3.28. Cap body 3.24 is preferably about 0.070 inches (1.8mm) thick and has a first face 3.26 on one side and a second face 3.28on a second side spaced from the first face 3.26, and the concavitydisplacement of second face 3.28 at the center is preferably about 0.030inches (0.76 mm). As with all embodiments, one or both of first orsecond faces may have a slight peripheral perpendicular “draft” or ridgeportion 3.27 extending from the face. The cap body 3.24 has a perimeter3.30 joining the first face 3.26 to the second face 3.28.

Adjacent faces 3.26, 3.28 of adjacent caps 3.22 are joined by at leastone connecting stem 3.32, preferably axially disposed in the center ofthe caps as shown, and preferably about 0.025 inches (0.64 mm) indiameter. Each stem 3.32 needs to be sufficiently flexible so as toallow the stacked caps to compress together when placed in the magazineof a nailer, and also needs to be shearable so that, when the bottommostcap of the stack is pushed into nailing position from the magazine, thestem 3.32 will shear or break to free the bottommost cap from the stack.The length of each stem 3.32, and thus the gap between adjacent caps3.22 when the stack is not compressed, is preferably about 0.060 inches(1.5 mm).

FIG. 10 is a simplified sectional view of the first and second halves3.34, 3.36 of the injection mold 3.38 used to make the third embodiment3.20 of the present invention, and is shown separated with the capsremoved. It shall be understood that well-known injection passagewaysand ejector pins are omitted from the drawing figures of the injectionmold for purposes of simplicity. In a manner well-known to those skilledin the art, each of the halves of the injector mold preferably haswell-known injector pins (not shown) for ejecting the molded caps fromthe mold, and the operation of the injector pins of one half of theinjection mold is sequenced with the operation of the injector pins ofthe other half of the injection mold so that the caps are first ejectedfrom one half of the mold and then from the other so that the connectingstems of the caps do not shear as might happen if some caps were ejectedfrom one half of the mold while other of the caps remained in the otherhalf of the mold. Additionally, to reduce the shearing of the capsduring ejection, preferably each cap of the third embodiment has aslight “draft” or ridge portion 3.27 on one side of the cap so that thecap is better retained into one half of the injection mold duringejection than in the other half of the injection mold. Each half of theinjection mold respectively has a plurality of semi-circular cavities3.40, 3.42 that together, when the injection mold is closed, form acircular cavity for molding the bodies 3.24 of caps 3.22. Each half ofthe injection mold respectively further has a semi-circular channel3.44, 3.46 that together, when the injection mold is closed, form acircular passageway between adjacent cavities 3.40, 3.42 to create theconnecting stems 3.32. Preferably, one of the halves of the injectionmold has a recessed cavity 3.48 for forming the ridge portion 3.27 ofeach cap in the mold.

Referring to FIGS. 13-18, the fourth embodiment 4.20 of the presentinvention is seen to be a plurality of stacked fastener caps 4.22, witheach cap having a cap body 4.24. Each cap 4.22 is substantiallyidentical to each other cap 4.22, so that a description of one sufficesfor all, except that the end caps only have a single connecting stem(hereinafter described) because the end caps only have an adjacent capon one side and not the other. The substantial difference between thefirst embodiment 20 and the fourth embodiment 4.20 is that the thirdembodiment has a transverse groove that is a flat midportion 4.50 acrossthe bottom or second face 4.28 so as to raise the underside of the capfrom the covering being secured to a building's surface, therebyproviding retaining tension by the cap to the covering when a fastenerholds the cap to the building's surface, as hereinafter described and asshown in FIG. 18. Cap body 4.24 is preferably about 0.070 inches (1.8mm) thick at first and second thicker portions 4.52, 4.54 outside oftransverse groove 4.50 and about 0.035 inches (0.9 mm) thick withintransverse groove 4.50 and has a top or first face 4.26 on one side anda second or bottom face 4.28 on a second side spaced from the first face4.26. As with all embodiments, one or both of first or second faces mayhave a slight peripheral perpendicular “draft” or ridge portion 4.27extending from the face. The cap body 4.24 has a perimeter 4.30 joiningthe first face 4.26 to the second face 4.28.

Adjacent faces 4.26, 4.28 of adjacent caps 4.22 are joined by at leastone connecting stem 4.32, preferably axially disposed in the center ofthe caps as shown, and preferably about 0.025 inches (0.64 mm) indiameter. Each stem 4.32 needs to be sufficiently flexible so as toallow the stacked caps to compress together when placed in the magazineof a nailer, and also needs to be shearable so that, when the bottommostcap of the stack is pushed into nailing position from the magazine, thestem 4.32 will shear or break to free the bottommost cap from the stack.The length of each stem 4.32 is preferably about 0.095 inches (2.4 mm),and thus the gap between adjacent caps 4.22 when the stack is notcompressed, is preferably about 0.060 inches (1.5 mm) at first andsecond thicker portions 4.52, 4.54.

FIG. 16 is an upward-looking view of one of the halves 4.34 of theinjection mold 4.38 used to make the fourth embodiment 4.20 of thepresent invention. The downward-looking view of the other of the halves4.36 of the injection mold 4.38 used to make the fourth embodiment issubstantially similar to the view shown in FIG. 16. It shall beunderstood that well-known injection passageways and ejector pins areomitted from the drawing figures of the injection mold for purposes ofsimplicity. In a manner well-known to those skilled in the art, each ofthe halves of the injector mold 4.38 preferably has well-known injectorpins (not shown) for ejecting the molded caps from the mold, and theoperation of the injector pins of one half of the injection mold issequenced with the operation of the injector pins of the other half ofthe injection mold so that the caps are first ejected from one half ofthe mold and then from the other so that the connecting stems of thecaps do not shear as might happen if some caps were ejected from onehalf of the mold while other of the caps remained in the other half ofthe mold. Additionally, to reduce the shearing of the caps duringejection, preferably each cap of the third embodiment has a slight“draft” or ridge portion 4.27 on one side of the cap so that the cap isbetter retained into one half of the injection mold during ejection thanin the other half of the injection mold. Each half of the injection moldrespectively has a plurality of semi-circular cavities 4.40, 4.42 thattogether, when the injection mold is closed, form a circular cavity formolding the bodies 4.24 of caps 4.22. Each half of the injection moldrespectively further has a semi-circular channel 4.44, 4.46 thattogether, when the injection mold is closed, form a circular passagewaybetween adjacent cavities 4.40, 4.42 to create the connecting stems4.32. Preferably, one of the halves of the injection mold has a recessedcavity 4.48 for forming the ridge portion 4.27 of each cap in the mold.

FIG. 19 shows one of the fourth embodiment caps 4.20 holding a covering56, such as roofing paper, to a board 60 of a building.

Referring to FIGS. 20-25, the fifth embodiment 5.20 of the presentinvention is seen to be a plurality of stacked fastener caps 5.22, witheach cap having a cap body 5.24. Each cap 5.22 is substantiallyidentical to each other cap 5.22, so that a description of one sufficesfor all, except that the end caps only have a single connecting stem(hereinafter described) because the end caps only have an adjacent capon one side and not the other. The substantial difference between thefourth embodiment 4.20 and the fifth embodiment 5.20 is that, ratherthan having a transverse groove 4.50 along one bottom face like thefourth embodiment 4.20, the fifth embodiment has a “bow tie” crosssection as shown, with first or top face 5.26 and bottom or second face5.28 both having a substantially flat transverse midportion or groove5.50 that angles upwardly at about 3.81 degrees to thicker first andsecond outer portions 5.52, 5.54 that are not as broad as the first andsecond outer portions 4.52, 4.54 of the fourth embodiment. Thisstructure makes the fifth embodiment reversible, such that regardless ofwhich face of the cap is adjacent to the covering on a building, thedownwardly-facing transverse midportion or groove 5.50 raises theunderside of the cap from the covering being secured to a building'ssurface, thereby providing retaining tension by the cap to the coveringwhen a fastener holds the cap to the building's surface. Cap body 5.24is preferably about 0.070 inches (1.8 mm) thick at first and secondthicker outer portions 5.52, 5.54 outside of transverse midportion 5.50and about 0.020 inches (0.5 mm) thick within transverse groove 5.50 andhas a top or first face 5.26 on one side and a second or bottom face5.28 on a second side spaced from the first face 5.26. As with allembodiments, one or both of first or second faces may have a slightperipheral perpendicular “draft” or ridge portion 5.27 extending fromthe face. The cap body 5.24 has a perimeter 5.30 joining the first face5.26 to the second face 5.28.

Adjacent faces 5.26, 5.28 of adjacent caps 5.22 are joined by at leastone connecting stem 5.32, preferably axially disposed in the center ofthe caps as shown, and preferably about 0.025 inches (0.64 mm) indiameter. Each stem 5.32 needs to be sufficiently flexible so as toallow the stacked caps to compress together when placed in the magazineof a nailer, and also needs to be shearable so that, when the bottommostcap of the stack is pushed into nailing position from the magazine, thestem 5.32 will shear or break to free the bottommost cap from the stack.The length of each stem 5.32 is preferably about 0.040 inches (2.4 mm),and thus the gap between adjacent caps 5.22 when the stack is notcompressed, is preferably about 0.060 inches (1.0 mm) at first andsecond thicker portions 5.52, 5.54.

FIG. 23 is an upward-looking view of one of the halves 5.34 of theinjection mold 5.38 used to make the fifth embodiment 5.20 of thepresent invention. The downward-looking view of the other of the halves5.36 of the injection mold 5.38 used to make the fifth embodiment issubstantially similar to the view shown in FIG. 23. It shall beunderstood that well-known injection passageways and ejector pins areomitted from the drawing figures of the injection mold for purposes ofsimplicity. In a manner well-known to those skilled in the art, each ofthe halves of the injector mold 5.38 preferably has well-known injectorpins (not shown) for ejecting the molded caps from the mold, and theoperation of the injector pins of one half of the injection mold issequenced with the operation of the injector pins of the other half ofthe injection mold so that the caps are first ejected from one half ofthe mold and then from the other so that the connecting stems of thecaps do not shear as might happen if some caps were ejected from onehalf of the mold while other of the caps remained in the other half ofthe mold. Additionally, to reduce the shearing of the caps duringejection, preferably each cap of the third embodiment has a slight“draft” or ridge portion 5.27 on one side of the cap so that the cap isbetter retained into one half of the injection mold during ejection thanin the other half of the injection mold. Each half of the injection moldrespectively has a plurality of semi-circular cavities 5.40, 5.42 thattogether, when the injection mold is closed, form a circular cavity formolding the bodies 5.24 of caps 5.22. Each half of the injection moldrespectively further has a semi-circular channel 5.44, 5.46 thattogether, when the injection mold is closed, form a circular passagewaybetween adjacent cavities 5.40, 5.42 to create the connecting stems5.32. Preferably, one of the halves of the injection mold has a recessedcavity 5.48 for forming the ridge portion 5.27 of each cap in the mold.

To use the stacked assembly of caps of all embodiments of the presentinvention, the stacked assembly of caps is inserted into the magazine ofa nailer just as with prior art caps. The well-known pusher of thenailer pushes the bottommost cap from the stack and into nailingposition, thereby shearing the connecting stem between the bottommostcap and its adjacent cap thereabove. A fastener, such as the staple 60shown in FIG. 19, is forcibly placed by the well-known nailer throughthe cap and covering 58 over a board 60 of a building, thereby causingthe cap to secure the covering to the board.

Although the present invention has been described and illustrated withrespect to a preferred embodiment and a preferred use therefor, it isnot to be so limited since modifications and changes can be made thereinwhich are within the full intended scope of the invention.

I claim:
 1. A plurality of stacked plastic fastener caps, each said capof said plurality of stacked caps having a cap body, said cap bodyhaving a first face and a second face spaced from said first face, saidcap body having a perimeter joining said first face and said secondface, with adjacent faces of adjacent caps of said plurality of capsbeing joined by at least one solid connecting stem; said adjacent capsand said at least one connecting stem being integrally molded therewith,in which said cap body of each said cap and said at least one connectingstem were integrally molded by injection molding and in which one ofsaid first or second faces has a ridge portion extending only partiallyalong said one of said first or second faces.
 2. A plurality of stackedplastic fastener caps, each said cap of said plurality of stacked capshaving a cap body, said cap body having a first face and a second facespaced from said first face, said cap body having a perimeter joiningsaid first face and said second face, with adjacent faces of adjacentcaps of said plurality of caps being joined by at least one solidconnecting stem; said adjacent caps and said at least one connectingstem being integrally molded therewith, in which said first face isconcave and said second face is convex and in which one of said first orsecond faces has a ridge portion extending only partially along said oneof said first or second faces.